Aqueous humour typically drains from the anterior chamber of the eye via the trabecular meshwork at the edge of the cornea. However, in some circumstances, overproduction of aqueous humour or reduced drainage of aqueous humour can increase intraocular pressure which can cause discomfort and/or damage the optic nerve. Accordingly, it would be desirable to be able to provide increased drainage of aqueous humour from the anterior chamber, particularly for glaucoma patients.